One type of porcelain produced in the imperial kilns during the Qianlong reign (1736-1795) of the Qing dynasty was commonly referred to as a “slip vase” or “vase with revolving inside”. Such vases were assembled from different pieces inside and out as well as for the top and bottom so that the inside of the body could revolve. This form of uncanny craftsmanship flourished in the Qianlong reign and was produced at the imperial kilns in Jing-de-zhen.The outer part of this vase with a revolving inside showing fish swimming--the part with tracings in gold over a sky-blue base--appears at first glance to be a single piece but is actually divided into three parts--1) the mouth and neck, depicted with a pattern of suspended jewels; 2) the shoulder, decorated with golden chrysanthemum petals, winding floral branches, and four small rings; and 3) the body and bottom--which have altogether four panels of openwork so that when the inner vase spins, one can clearly see goldfish swimming leisurely in the greenish water. Each part was originally first fired separately and then after completion put together and fired with low-temperature glaze to fuse them. Usually “slip vases” from the Qianlong kilns were composed of an inner and outer part assembled using the mortise and tenon method so that they could move freely, which is the key to a successful vase with a revolving inside. Close examinations shows where the body and shoulder meet with low-temperature glaze fired to connect them. The rim line on the shoulder is so obvious that although adorned with gold decoration, the original traces of the structure are quite clear.The vase with revolving inside was a new type researched and developed by the Ceramics Superintendent of the imperial kilns in the Qianlong reign--Tang Ying--and his assistant Lao-gu, who brought the level of technical expertise and craftsmanship of porcelains at the time to new height.